In order to create a feeling of comfort and luxury, material such as leather is often employed to cover an interior part, such as vehicle door trim panel. Due to soft property of the leather material, it can be difficult to assemble the leather to the vehicle door trim panel in an efficient manner. One solution is to form the intermediate part firstly, then connect the leather to the intermediate part, and finally connect the intermediate part to the vehicle door trim panel, for instance via welding.
The above solution is not only time inefficient, but also noise may be caused by the connection between the intermediate part and the vehicle door trim panel.